Try holding your hand on the intake while cranking. Take off the seat & cover up the rubber air intake horn with your hand. You should feel suction every time the motor spins around. If it doesn't seem to have any vacuum, I bet it is a piston skirt. Not really that terrible expensive to fix as long as no pieces got into anything else.
farmr

 

Yea it has good vacuum if i put my hand over the intake boot. I took my carb apart and cleaned it with carb cleaner too. My plug doesn't look totally dry now when i take it out but it isn't that wet either. I'm still just getting an ocassional backfire when i try to start it. Stupid piece of crap polaris!!! lol

 

albino,

You have seized the motor. I had the same thing happen to me at Cochranton this year. Tear down the motor and you'll probably find that the rings are sticking to the piston.

 

Before you do anything else, try cranking while spraying wd-40 in through the back of the carb. Your problem sounds like fuel starvation rather than any of these other possibilities. If the plug is dry after trying to start, then the problem is the motor's not getting any fuel. I think you will find that to be the problem. If the engine's not getting any gas, check fuel lines and carb for something obstructing the way. Is the gas tank full, and if not, is it turned to the reserve fuel position? Let us know what you find out.